Method for manufacturing a heat exchanger



WAHEl KIKUCHI E L METHOD FOR MANUFACTURING A HEAT EXCHANGER Nov. 21,1967 3,353,250

Filed March 24, 1964 2 Sheets-Sheet 1 INVENTORS ATTORNEY Nov. 21, 1967WAHEI KIKUCHI ET 3,353,250

METHOD FOR MANUFACTURING A HEAT EXCHANGER Filed March 24, 1964 2Sheets$heef 2 INVENTORS mnannulw ar-04025 BY- Qiawg.

ATTORNEY United States Patent 2 Claims. 01. 29-1513 The presentinvention relates to a method of manufacturing a heat exchanger.

In gas separators and the like a great number of Hampson heat exchangersare employed as the most important main instrument. Hampson heatexchangers are illustrated in the patents to Hampson, No. 1,896,080 and1,896,081. This type of heat exchanger may comprise a heat conductingtube made of thin copper tube and wound about a core metal 20 to 50times through spacers. When a heat exchanger of a very large length incomparison with the coil diameter is made, there are many difficultiesin designing and manufacturing. In other words, with a heat exchanger aslong as 7 in. (about 23.3 ft.) the core metal has to be madeconsiderably thick or the heat exchanger itself has to be divided intotwo parts so as to keep the flexure of the exchanger owing to its ownweight during winding of the heat conducting tube under a certain value.An example of a wound heat exchanger that is wound in two parts andsubsequently connected together by soldered sleeves (15) is found in thepatent to Giauque, Patent 2,508,247, issued May 16, 1950. This patentalso illustrates the above mentioned spacers 14 that are used when theheat exchanger tube is wound in multiple layers; also, this patentillustrates the manifold 19 for connecting the tubes of the multiplelayers together. Accordingly the whole plant, as well as the heatexchanger itself becomes very large in size, and construction cost andother expenses rise in the manner of a geometric progression.

The present invention provides a method of manufacturing a heatexchanger in which the diameter of a core metal can be determined notfrom the viewpoint of strength but from the viewpoint of heat conductingefiiciency. In detail, a heat exchanger made by this method uses asupport ring which has a proper number of notches through which a heatconducting tube passes and supports a core metal at one or more pointsexcept at the two ends of the metal, and a support table with rollersrotatably supporting the support ring. The method is characterized inthe way of winding the heat conducting tube; namely the tube is woundabout the core metal through the notches of the support ring as the coremetal is supported through the support ring and is rotated together withthe support ring.

Further detail of the invention will be explained in reference to theaccompanying drawings.

FIGURE 1 illustrates a wound type of prior art heat exchanger with itsdrum cut away and the tubes partly in section;

FIGURE 2 illustrates a wound type heat exchanger that has been made bythe method of the present invention;

FIGURE 3 illustrates a conventional heat exchanger winding apparatusemploying the apparatus 6 and 8-10 of the present invention method;

FIGURE 4 is a front view of the support ring of the present inventiontaken along line AA of FIGURE 3; and

FIGURE is a partial view similar to FIGURE 2 illustrating the winding ofa heat conducting tube while using the support ring of the presentinvention.

Reference numeral 1 in FIG. 1 is a core metal; 2 and 3,353,250 PatentedNov. 21, 1967 ice 3 are brackets supporting the ends of the core metal1; 4 is a heat conducting tube; and 5 is a drum. The multiple layers ofthe coiled heat exchanger tube 4 are held apart from each other byspacers 11 in a conventional manner as shown in the above-mentionedprior art patent to Giauque with spacer strips 14. In FIGURE 2, the oldelements that per se form no part of the present invention aredesignated by numerals that are identical to the numerals used in FIGURE1 so that the features of the present invention may be clearly set apartfrom the prior art. Numeral 6 indicates a support ring to support thecore metal 1 at one or more points except at the two ends of the coremetal (in the present embodiment at one point in the central portion ofthe core metal); 7 indicates notches formed radially in the support ringin order to pass the heat conducting tube 4; and 8 is a support tablewith two rollers 9 and 10 to rotatably support the support ring 6.

In FIGURE 3, a prior art heat exchanger winding device 1217 is shownemploying the apparatus of the present invention for winding a heatexchanger coil according to the method of the present invention, A motor12 is used to drive the shaft of a suitable chuck 14; the chuck shaft issupported in the bearing 13. The bearing 13 and motor 12 are suitablymounted on a stationary support 16. The chuck 14 is used to hold thebracket 2 and a similar chuck is used to hold the bracket 3. The chuckfor the bracket 3 is freely supported in a bearing block 15 that is inturn supported on a stationary support 17. The support ring 6 and itsbearing structure 8-10 of the present invention is used with the abovedescribed conventional heat exchanger coil winding device to practicethe method of the present invention.

In the process of winding the heat conducting tube about the core metal,the core metal 1 and the support ring 6 are made to rotate by apower-driven rotating device as the core metal is supported by thesupport table 8 with rollers through the support ring 6. And the heatconducting tube 4 is wound about the core metal 1 through spacers 11many times, for example from the right end of the core metal. When theheat conducting tube 4 reaches the central portion of the core metal 1,the tube is passed from the right half to the left half of the coremetal through one of the notches 7 of the support ring 6 and wound on.

Thus, according to the present invention winding of a heat conductingtube can be performed as the core metal is supported at one point otherthan its two ends. Therefore the substantial span of the core metal andthereby the moment of inertia of the core metal can be reduced. Thatenables use of a core metal of a much smaller diameter, and moreoverassures safe and easy performance of winding process of a heatconducting tube. Thus not only the heat exchanger itself but also thewhole plant can be made much smaller in size. And material cost,construction cost and other expenses can be largely cut down. Further,since it is not necessary any more to divide the heat exchanger into twoparts, better heat exchanging efiiciency, maintenance and operation canbe expected.

According to the present invention the portion around the support ringis incompletely wound with the heat conducting tube as indicated in thecentral portion of FIG. 5. But the substantial length of the portion isonly 20 cm. (about 8 inches). Lengthening of the total length by 20 cm.solves the problem.

What is claimed is:

1. In a method of manufacturing a wound tube heat exchanger ofrelatively great weight and axial extent on a relatively weak coreselected for its efiect on the heat exchanger independently of itssupport characteristics,

including the steps of providing a core having opposed ends, rotatingsaid core about an axis through its ends, winding a Continuous heatexchanger tube helically around said core in multiple layers from oneopposed end to the other opposed end of the core, wherein theimprovement comprises: supporting the core between its opposite ends bya drivingly connected support ring; supporting the support ring in abearing for rotation with the core; helically winding the tube first onthe core between one end of the core and the support ring; thereafterpassing the tube, intermediate its terminal ends, radially through aradially extending outwardly opening slot in the support ring; andthereafter helically winding the tube on the core between the otheropposed end of the core and the support ring.

2. The method according to claim 1, including the step of providing thesupport ring with an outer substantially circular surface broken only bythe slots and supporting this outer circular surface on spaced rollersrotatably mounted in a stationary support below the core.

References Cited UNITED STATES PATENTS 3/1895 Heath 140-92.2 2/1941Price.

1. IN A METHOD OF MANUFACTURING A WOUND TUBE HEAT EXCHANGER OFRELATIVELY GREAT WEIGHT AND AXIAL EXTENT ON A RELATIVELY WEAK CORESELECTED FOR ITS EFFECT ON THE HEAT EXCHANGER INDEPENDENTLY OF ITSSUPPORT CHARACTERISTICS, INCLUDING THE STEPS OF PROVIDING A CORE HAVINGOPPOSED ENDS, ROTATING SAID CORE ABOUT AN AXIS THROUGH ITS ENDS, WINDINGA CONTINUOUS HEAT EXCHANGE TUBE HELICALLY AROUND SAID CORE IN MULTIPLELAYERS FROM ONE OPPOSED END TO THE OTHER OPPOSED END OF THE CORE,WHEREIN THE IMPROVEMENT COMPRISES: SUPPORTING THE CORE BETWEEN ITSOPPOSITE ENDS BY A DRIVINGLY CONNECTED SUPPORT RING; SUPPORTING THESUPPORT RING IN A BEARING FOR ROTATION WITH